After statement execution results can be retrieved at once to be buffered
by the client or by read row by row. Client-side result set buffering
allows the server to free resources associated with the statement
results as early as possible. Generally speaking, clients are slow
consuming result sets. Therefore, it is recommended to use buffered
result sets. mysqli_query() combines statement
execution and result set buffering.

PHP applications can navigate freely through buffered results.
Navigation is fast because the result sets are held in client memory.
Please, keep in mind that it is often easier to scale by client than
it is to scale the server.

If client memory is a short resource and freeing server resources as
early as possible to keep server load low is not needed,
unbuffered results can be used. Scrolling through unbuffered results
is not possible before all rows have been read.

Example #3 Navigation through unbuffered results

<?php$mysqli->real_query("SELECT id FROM test ORDER BY id ASC");$res = $mysqli->use_result();

The mysqli_query(), mysqli_real_query()
and mysqli_multi_query() functions are used to execute
non-prepared statements. At the level of the MySQL Client Server Protocol,
the command COM_QUERY and the text protocol are used
for statement execution. With the text protocol, the MySQL server converts
all data of a result sets into strings before sending. This conversion is done
regardless of the SQL result set column data type. The mysql client libraries
receive all column values as strings. No further client-side casting is done
to convert columns back to their native types. Instead, all values are
provided as PHP strings.

It is possible to convert integer and float columns back to PHP numbers by setting the
MYSQLI_OPT_INT_AND_FLOAT_NATIVE connection option,
if using the mysqlnd library. If set, the mysqlnd library will
check the result set meta data column types and convert numeric SQL columns
to PHP numbers, if the PHP data type value range allows for it.
This way, for example, SQL INT columns are returned as integers.